Richard Heene, the father of a missing 6-year-old who was found hiding at his Colorado home today after authorities believed he'd ascended in an untethered balloon, often put his children in danger, a former business partner said.
The story had a happy ending, but child safety experts said the incident underscored the vigilance parents must exercise to keep children safe and avoid tragedy.
Heene, a "storm chaser," loved science but would often put his children at risk, said the father's friend and former research partner, Barbara Slusser.
Slusser worked with Scott Stevens and Heene -- the father of Falcon Heene, 6, and two older boys, Bradford and Ryo -- at the Science Detective Research Group in Fort Collins, Colo.
"He loves those kids dearly, but part of the reason my co-host Scott and I split from him is because we felt Heene put his kids in the line of fire a bit too much," Slusser said.
"The last straw for us was when Hurricane Gustav and Hurricane Ike were heading toward the Texas coastline and Heene wanted to go back there and take the kids," she said.
Heene's neighbor, Tina Sanchez, told ABC News that Falcon is "a great kid, very adventurous, and has no fear factor. For him to climb into this balloon would not be out of character. He has a high tolerance for cold, often running around without a jacket."
Slusser, Heene's ex-business partner, said she split from Heene shortly after the summer of 2008.
"Those kids went everywhere with us," she said. "We took those kids tornado chasing.
"They loved it," Slusser added. "They grew up doing this."
Slusser said that Heene had no degrees in science but liked to surround himself with people who did, like Slusser.
"He raised those kids to be scientists, and he wanted them to be scientists and exposed them to science at every possible level," said Slusser.
"He loves those kids and his wife loves those kids, but I don't think they know boundaries -- especially Richard," said Slusser.
Slusser said she hoped Falcon -- known by friends and family as "Falcy" -- was simply hiding, and as it later turned out, he was.
Parents and child safety experts said parents can never be too vigilant with their young children.
Accidents and unintentional injuries are the No. 1 cause of death among young children, according to the Centers for Disease Control and Prevention.
Each year, the CDC reports 4,631 deaths among children aged 1 to 4, and another 6,149 deaths among children aged 5 to 14.
"This is obviously an unusual case," said Dr. Gary Smith, director of the Center for Injury Research and Policy at Nationwide Children's Hospital in Columbus, Ohio.
"If you were to think of this generically as being curious and exploring the environment and copying what you are seeing adults do and not seeing danger, this is a typical scenario," he said. "Child safety is an afterthought."
Smith said that while supervision is important in guarding a child's safety, it cannot be a parent's sole strategy.
"You can't watch a child 100 percent of the time," said Smith, who is past chairman of the American Association of Pediatrics' committee on injury, violence and poison prevention.
"If you rely on constant vigilance, it's going to fail," Smith told ABCNews.com. "We have to take care of our other kids and cook dinner."
What parents need to do is to address the dangers in the environment in what he calls an "automatic passive prevention system."
"You don't do things that invite an opportunity for a child to put himself in harm's way," he said. "Keep things locked up, install mechanisms children can't defeat."
Dr. Benjamin Hoffman, an associate professor of pediatrics at the University of New Mexico, agreed.
Today's balloon incident "highlights the need for constant vigilance," he told ABCNews.com. "Six-year-olds are curious, and given the opportunity, these things will happen."
"I think every parent has a there-but-for-the-grace-of-God moment," said Hoffman. "Events like this reinforce we can never afford to get complacent with the safety of our children.
A typical 6-year-old is in kindergarten or the first grade, and boys tend to be the most adventurous, according to Hoffman.
"The most common injuries are falls out of trees and on trampolines," he said. "Young school-age kids get into kitchen and garage tools, crawl into trunks and get trapped in confined spaces, because they like to investigate how the world works."
His advice to parents is to "be as prepared as you possibly can. It's a balance between giving kids freedom and opportunity."